Apparatus for producing ornamental background on stone



March 27, 1928. 1,664,159

' E. A. CHASE V APPARATUS FOR PRODUCING ORNAMENTAL BACKGROUND 0N STONE Filed April 23- 1926 JZ- J5. .10

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Patented Mar. 27, 1928.

UNITED STATES ELROY A.v cruise, on nonrnrrnnn', VERMONT. I

APPARATUS FOR PRODUCING ORNAMENTAL BACKGROUND ON S'lOhTLIiL' Application filed April 23, 1926. Serial No. 104,193.

This invention relates to apparatus for use in producing an ornamental background in sand blast work on granite or other similar stone.

In producing such work, difficulty: has been encountered in securing a satisfactory contrast between the background and the raised design, particularly when using one An 1mof the lighter colored granites. roved method of producing a contrasting Eackground has been invented and prevlously patented by S'anbor-n and 'Haslam, No.

1,500,272, dated July 8, 1924. v

It is the object of my present invention to provide certain improved apparatus adapted to be used in the Sanborn and Haslam process.

My invention relates more specifically to the provision of an improved form of sand obstructing device or screen to be interposed in the path of the sand blast and thus assist in producing a contrasting surface on the background.

My invention further relates to certain arrangements and combinations of parts which will be hereinafter:described and more particularly pointed out in the appended claims.

Two forms of the invention are shown in the drawings in which Fig. 1 is a plan view of one form of the invention;

Fig. 2 is a transverse sectional elevation, taken along the line 2-2 in Fig. 1;

Fig. 3 is a longitudinal section, taken along the line 33 in Fig. 1;

Fig. 4 is a. plan view of a second form of my invention;

Fig. 5 is an enlarged partial plan view;

Fig. 6 is a partial transverse sectional elevation, taken along the line 66 in Fig. 5;

, Fig. 7 is a partial longitudinal section, taken along the line 7-7 in Fig. 5; and

Fig. 8 is a plan view of a design produced by the use. of my improved screen.

Referring particularly to Figs. 1 to 3, I have shown a sand obstructing device or screen, comprising a rectangular frame formed of side members 10 and end members 11, said side and end members being rigidly and permanently secured at the corners thereof. A series of parallel adjacent notches or slots 12 are formed in the lower edges of the side members 10 and are adapted to receivea plurality of cross bars 13 which are a drive fit in the slots 12. These bars 13 are of relatively slight thickness but'are of substantial width, and

extend from side to side of the rectangular frame, being secured at their opposite ends iirthe side members 10. The cross bars '13 are preferably formed of steel and for the most eflfective operation, the. bars 13 are hardened andteinpered before being placed in the screen frame.

The frame with its cross bars isplaced againstthe surface of the stone in which a; design has been producedby a. sand blast and the sand blast is thereafter directed through the bars against the background, before removing the protecting'coating of gelatine or other similar material from the face of the stone. i

The background will thus be sunk slightly deeper than before, but the portions of the background under or aligned with the cross bars 13 willbe left without further depression, thus forming a contrasting back ground of closely adjacent parallel raised lines of stone, as shown in Fig. 8.

This form of screen has certain advantages over the rectangular mesh wire screen shown and described in the Sanborn'and Haslam patent. 'One of these advantages is the increased sharpness of the lines produced in the background, as the relatively broad side faces of the bars 13 direct the sandblast perpendicularly against the surface of the background, whereas with the wire screen a certain amount of angular approach of the sand was permitted.

I find it to be of substantial advantage to use hardened and tempered or resilient steel bars, as these bars not only resist the wear of the sand blast more effectively, but they also retain their positions more accurately, even when the temperature of the bars is substantially raised by the friction of the sand.

Referring now to Figs. 4 to 7, I have 7,

shown a second. form of screen or sand obstructing device, in which the cross bars 20 are provided with openings 21 at their ends through which extend tie-rods 22. Spacing members or washers 23 hold the cross bars 20 in the desired spaced'parallel relation. also secured by the tie-rods or bolts 22, and these end members, together with the Rigid end members 24 are I I tie-rods 22 and the spacing members 23,

firmly clamp the bars 20 together in spaced relation and form a rigid supporting frame for said cross bars.

The use and operation of this type of screen or sand obstructing device is identical with that previously described.

Having thus described my invention and the advantages thereof, Ido not Wish to be limited to the details herein disclosed otherwise than asset forth in the claims, but what I claim is 1. In a sand blasting apparatus, a sand obstructing device for producing an ornamental back ground, said device being adapted to be interposed in the path of the sand blast adjacent the surface of the Work, and comprising aplurality of thin, flat, elongated, steel bars, and means to firmly support said bars substantially parallel and with their flat side faces substantially perpendicular to the surface of the Work.

2; In a sand blasting apparatus, a sand obstructing device for producing an ornamental background, said device being adapted to be interposed in the path of the sand blast adjacent the surface of the Work, and comprising a plurality of thin, flat, elongated, steel bars, and means to firmly support said. bars in adjacent parallel relation With their side faces substantially perpendicular to the surface of the Work, said bars being hardened and resiliently resisting distortion from Wear or heat.

3. In a sand blasting apparatus, a sand obstructing device for producingan ornamental background, said device being adapted to be interposed in the path of the sand blast adjacent the surface of the Work, and

comprising a plurality of thin, flat, elongated, steel bars, and a rigid open rectangular, frame having notches in the lower portions of the side frame members, inwhich notches said bars are inserted with adrive fit. I

In testimony whereof I have hereunto affixed my signature.

' ELROY A. CHASE. 

